Answer
$2$
Work Step by Step
RECALL:
$\log_a{(a^n)} = n, a \gt 0, a \ne1$
Since $25=5^2$, the given expression is equivalent to:
$\log_5{(5^2)}$
Using the property above gives:
$\log_5{(5^2)} = 2$
Thus, $\log_5{25} = 2$.